Conventional LTE (Long Term Evolution) cellular networks typically include a core network, a RAN (Radio Access Network), and one or more mobile communication devices (UE or user equipment).
The radio access network (RAN) resides between user equipment (UE) such as a mobile phone, a computer, or any remotely controlled machine and provides connection with its core network (CN). As its name suggests, the radio access network provides respective user equipment access (such as Internet access) via the core network.
In certain instances, conventional LTE networks offer both voice and data services to user equipment via a single subscription such as a single SIM (Subscriber Identification Module). As well known, a subscriber identity module (SIM) is an integrated circuit that securely stores information such as the International Mobile Subscriber Identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers). It is also possible to store contact information on many SIM cards.
A new-shared spectrum scheme is being introduced in the United States at 3.5 GHz called CBRS (Citizens Broadband Radio Service). This new band can be used to support LTE communications.